NUMERICAL-SIMULATION OF PULSED EDDY-CURRENT NONDESTRUCTIVE TESTING PHENOMENA

A general-purpose hybrid finite element and finite difference computational model has been developed for the prediction of pulsed eddy-current distribution in metals for nondestructive testing purposes. The numerical model employs an axisymmetric formulation to study coil configurations suspended over a metallic specimen. As a driving function, a pulsed Maxwell-distributed current density is applied. Resulting eddy-current distributions are discussed as a function of conductivity, permeability, and lift-off. Furthermore, the transient voltage response of a coil over an infinite half-space is numerically computed and compared to the solution obtained by a novel analytical approach. The numerical model is then employed to determine the induced voltage due to a surface-breaking flaw. © 1990 IEEE